A-not-B error

The A-not-B error occurs when infants or young children repeatedly search for an object where they last found it (position A), even after seeing it hidden elsewhere (position B). This happens because their developing memory and understanding of object permanence are still maturing. Instead of recognizing that the object has moved, they default to their familiar pattern of searching at A. This error highlights how cognitive processes like memory, attention, and learning are developing, and it typically diminishes as children gain better reasoning skills around 12 months of age.